diff -u b/core/lib/Drupal/Core/Entity/EntityRenderController.php b/core/lib/Drupal/Core/Entity/EntityRenderController.php
--- b/core/lib/Drupal/Core/Entity/EntityRenderController.php
+++ b/core/lib/Drupal/Core/Entity/EntityRenderController.php
@@ -34,9 +34,17 @@
 
     // Initialize the field item attributes for the fields set to be displayed.
     foreach ($entities as $entity) {
+      // The entity can include fields that aren't displayed, and the display
+      // can include components that aren't fields, so we want to iterate the
+      // intersection of $entity->getProperties() and $display->getComponents().
+      // However, the entity can have many more fields than are displayed, so we
+      // avoid the cost of calling $entity->getProperties() by iterating the
+      // intersection as follows.
       foreach ($displays[$entity->bundle()]->getComponents() as $name => $options) {
-        foreach ($entity->get($name) as $item) {
-          $item->_attributes = array();
+        if ($entity->getPropertyDefinition($name)) {
+          foreach ($entity->get($name) as $item) {
+            $item->_attributes = array();
+          }
         }
       }
     }